Coil



H. H. IDE

` June 12, 1928.

COIL Y fiar-2579".'

Filed DBG. 4, 1924 Patented .lune 12, 1928.

UNITED sTrftTEsy AiatrelaTA OFFICE.

HARRY H. IDE, E LA GRANGE,` ILLINOIS, ASSIGNOR TO KELLOGG SWITCHBOARD AND SUPPLY COMPANY,` OF CHICAGO, ILLINOIS, A CORPORATION lOIE ILLINOIS.

COIL.

.appnmicn` med December 4, 1924.. serial No. 753,926.

My invention relates to coils or transformers, and has to do more particularly with transformers of the air core type, which in the wireless or radio art, are known as radio frequency transformers and which are used in circuits of radio receiving sets, although the coils are adapted to be used for many other purposes.

In radio frequency transformers of the above type, the primary and secondary windings eachk comprise` a. plurality of turns or convolutions, of wire wound upon a suitable supporting tube of insulation material. It

has been found that largelosses occur, due l5 to leakage of the coils and materialcapacity owing to the fact that the convolutions `of wire are in contact with the supporting tube, and an object of my invention is to construct a transformer of the above type, which will obviate a large percentage of the loss found in coils of the prior art.

A feature of my invention is the provision of an improved'coil of the above type,- in which each layer of the primary winding of the coil engagesy the convolutions of adjacent layers of the secondary winding to obtain close coupling between the primary and sec-,

ondary windings of the coil.

Another feature of my invention is the novel means employed in winding the coil f of my invention in which each convolution of the primarywinding of the coil lies between two adjacent layers of convolutions of the secondary winding and in which the completed coil is self-supporting without the use of any substance, such as shellac or the like, for holding the turns of wire in posi tion. The features just pointed out, as well as others, relating to details of construction and combinations of parts, will be hereinafter more particularly pointed out in the ensuing specification andy appended claims.

For amore complete understanding of my invention, reference may be had to the accompanying drawings in which like reference characters in the several views denote like parts, and in which:

Fig. .1 is a face view of the transformer coil of my invention;

Fig. 2 is a right Side view of Fig. l;

.ing drawing is 'tenin number.

F ig. 3 is a reverse face View of the transformer coil, and l y F ig. 4 is a sectional view along the line 4 4 of Fig. 2.

Referring now more in detail to my invention as yillustrated in the accompanying drawing, the transformer coil of my inven-v tion is ring shaped and comprises a primary winding P and a. secondary winding S and for the'purpose of winding the transformer 0f my invention, I provide a suitable winding mandrel with two parallel rows of removable pins equally spaced apartaround the periphery of the winding mandrel but stagered in relation to each other in the two rows yfor purposes as will presently be described. In placing the first layer 3 of convolutions on the mandrel the inside terminal 2 of the'secondary winding S is anchored to suitable means on the mandrel and upon rotation of the mandrel the first layer 3 of convolutions of wire of the secondary winding S is pla-ced upon the mandrel between the two parallel rows of pins in the mandrel, and which as illustrated in the accompany- After the first layer 3 has been placed .upon the mandrel, the first turn 5 of the primary winding P is now placed over the first layer 3 of the secondary winding S. The inside terminal 4 of the primary winding P is anchored and the first turn 5 of the primary is woven in and out around the tworows ofk pins permitting the turn 5 of the primary winding P to be placed thereon in a zigzag form due to the staggered relation of the 'pins in the two parallel rows. After the first turn 5 of theprimary winding has been placed onthe rst layer 3 of convolutions of the secondary winding S, the next layer of convolutions of the secondary winding S is placed on top of the first turn 5 of the primary Awinding P, and successive layers and turns of the secondary and primary windings S and P are placed on. the mandrel until the requisite number" of turns or layers of the secondaryk winding S have been placed thereon and the requisite number of turns of the primary winding P have been placed thereon. After this building up of the primary yand secondary windings P and S has been accomplished, thel terminal ends 7 and 8 of the respective windings P and S are temporarily secured until the coil can be fastened together tofform a unit structure. To secure the turns of the coil in position and to form a unitary self-supporting Structure, a binde-r twine or cord 10 is woven through thealigned loops 1l andi?l of the turns of the primary windings P, protruding from the respectivesidesl and 14 of the com pleted coil, which secures the layers 3 of the secondary winding S against displacement,`

and also secures the turns 5 ot the primary winding P against displacement. It is, of course understood, that the wire which forms the primary andl secondary windings is wire duce a coil or transformer in which is ob! tained close coupling veffect between the primaryand secondary windings P and S and in which the successive layers ot the secondary winding Sv are equallyI spaced by the turns on the primary winding' P and the turns of theprimary winding P are in turn snaced apart bythe layers of the secondary winding S. Y u

While l have described a. particular form ot coil and a. specific number of turns VJfor the primary and secondary windings P and S, it is readily understood thatV diierent size coils may be constructedwith different ratios ot turns between the primary and sec-y ondary windings P and S, and that structuralv cha ages will readily suggest themselves to thoseskilled inthe art, without dev parting from the spirit of the invention, and I, thereto-re, ann to cover allV such changes of convolutions andormi-ng theinnerm'ost and outermost layers'and the alternate layers throughout the said transform-er, said primary windingl comprising a strand ot wire wound back and forth across the faces of the layers Vof said secondary winding and lyingbetween adjacentV layers and engaging the convolutions of the layers of said seo ondary'wind'ing to maintain the. 'said' layers in spacedrelation, and means wound around the layers of the said primary and said secondary to hold the layers in position relative to each other. p

2. A transformer of the character described including a primary winding and a secondary winding, said secondary'windingv comprising a strand of wire'wound in concentric layers of convolutions, said winding Jrorming the innermost layerupon which' 'the remainder of th-e transformer is' woundand the outermost layer which Vassis-ts in securing the other layers in position, said primary windingcomprising a strand ot 'wire wound back and forth across the faces 'of the layers ot said secondary windingand lying between adjacent layers and engaging the conyolutions of the layers. of said secondary wind# ing and serving toiseparate the layers O -t said secondary winding, said primary wind'- ing extending outside the layers of thesa'id secondary winding", and a binding cord wound around the layers of the said primary and secondary and extending through the en# tended portions of said primary to hold vthe said layers in position relative'to each other. Signedby me at Chicago,A inv the .county of Cook and State of Illinois, thisQfd day of December, 1924.' ,HARRY H. lDE. i 

